ML19329A807
| ML19329A807 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/28/1977 |
| From: | Miller D TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML19329A801 | List: |
| References | |
| NUDOCS 8001150703 | |
| Download: ML19329A807 (3) | |
Text
....
)h LICENSEE EVENT REPORT
~
Co= raat stoCs LLJ l l l l i
_s
f.*au' '
",9ti '
< vJ.~ '
s oc ~,. ~em..
E.lolH IDlB1S11j lt6 l Ol -l Gl 01 Ni P]F l-l0 l 3; }4 1J1 11 1]I l 6N. 3I$
i.- i, n a ao
.a,,co..::sr ceeen
~
,,o.....v...
...e.,,a.,
...o.,om..
5 1 61..i 6l 3 4 I}t Or 8,2,9 7,7 1 161912181717 1
6 3
Coa'i p y G p 1 61 avawr ce sCaiPrio=
g, Reactor Coolant System Tave was less than 525 F in Mode 2, Startup. This; g' placed the unit in the Action Statement of Technical Specification The reactor was shutdown within twelve miautes as required by 'I m
@l 3.1.1.4.
.s u
E [_the Action Statement.
(NP-33-77-73)
]
3
- s
=
l_
l 0
ca amme at coor "su
. a" naaTu"e7c"v'eIn't a o>i Ei h c'nYt veos a e som (DJ i z i zi z i zr z i zi - t_zJ i..zizi ziz l (NJ 7
89 so at 62 47 3
.3 as CAUST oESCm8 piton
@l The cause is due_t,o.both procedure error in the shutdown procedure.
I
@' l PP 1102.10.1 and the fact that only three Reactor Coolant Pumps were in I
=o w
as a
@l operation.
I a se ao
'% s EUS' ceWo otSCovteev D.SCnertoom p_j i 6EilII"6l gl ose.e a status av NA l (Aj
[%~
j NA ii 7
0 9
10 42 dl me '
oe S"e'i"b a
auovees or aCisvety toCatsoes er attEast
(_z_),[Y,z 1 NA -
l l NA I
i
.o PER$oNNEL EMPoSURES mveeme n t vec ca.sceseveon Q7,' 61 61 61 LE I NA l
is l9 si s2 13 50 Pf ftsoNM(t INJusetts neuwet
- o. se mes tioes QiaL61Ofbl [ NA l
3 5
in tJ ao o0 9st1t CorestOutNCES 8 5 l NA I
e u
LOSS on oaheAGE To 0 ACILif v
@,tver 1 NA i
otsC a ses soas z
(
a o
. To w
i PUst:Civv -
mr l NA l
~
s es n
aoottloseAt s ACTORS Ql NA
> es
d f.d91 1
y' Dale Miller (419} 259-5000, Ext. 274 DVR #119-1 8001150 703
T I
TOLEDO EDISON COMPANY kj DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION SUPPLEMENTAL INFORMATION FOR LER NP-33-77-75 DATE OF EVENT: August 29, 1977 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Reactor Coolant System Tave less than 525 F.
.:onditions Prior to Occurrence: The plant was in Mode 2, with Power (MWI) = 0 and Load (MWE) = 0.
Reactor Coolant System pressure was 2155 psig and tempera-'
ture was 5320F. Reactor power was being decreased from approximately 10-6 amps to approximately 10-8 amps. Preparations were being made to allow maintenance to inspect the Reactor Coolant Pump 1-1-2 Surge Capacitors.
Description of Occurrence: At 0117 hours0.00135 days <br />0.0325 hours <br />1.934524e-4 weeks <br />4.45185e-5 months <br /> on August 29, 1977, the Main Feed Pump was removed from service. The Startup Feed Pump was on to provide minimum feed-water flow to the steam generators. At 0120 hours0.00139 days <br />0.0333 hours <br />1.984127e-4 weeks <br />4.566e-5 months <br />, average Reactor Coolant Sys-tem temperature decreased to 5250F, and continued to decrease. This placed the station into the Action Statement of Technical Specification 3,1.4.
The Techni-j cal Specification requires average reactor coolant temperature (Tavg) to be main-tained at / 52507 while the reactor is critical. If Tavg decreases to less than
~
i l
5250F, the station must be in Hot Standby within 15 minutes.
When Tavg decreased to 5250F, the turbine bypass valves were shut momentarily to maintain system pressure. Gland Steam was transferred to the Auxiliary Boiler and the Main Steam Line Warm-up Valves MS 1299A and MS 1299B were closed, to reduce stesa consumption.
The Shift Foreman ordered the ree.ctor shutdown. At 0129 hours0.00149 days <br />0.0358 hours <br />2.132936e-4 weeks <br />4.90845e-5 months <br />, the reactor re-gulating rods were fully inserted. A shutdown margin calculation was performed and the reactor was verified to have a shutdown margin of 4.73% delta K/K. The 0
~ inimum Tavg temperature reached was 512 F.
The Operations Enginaar was informed m
of the occurrence.
Designation of Apparent Cause of Occurrence: A procedural error was one cause of this incident. The Shutdown and Cooldown Procedure, PP 1102.10.1, did not address i
putting the Auxiliary Boiler on and switching steam loads to the Auxiliary Boiler until after reactnr power had been decreased to 10-8 amps.
1 j
I Contributing factors include the decay heat production of the new core was minimmi and only three Reactor Coolant Pumps (RCP) were runnf*1g at the time. RCP l-1-2 l
was out of service due to the failure of the surge capacitor at 1740 hours0.0201 days <br />0.483 hours <br />0.00288 weeks <br />6.6207e-4 months <br /> on August 27, 1977.
l l O o
i'
m r
. TOLEDO EDISON COMPANY DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION SUPPLEMENTAL INFORMATION FOR LER NP-33-77-75 PAGE 2 i
i f
)
Analysis of Occurrence: The health'and safety of the public and station employees was not endangered. As a result of this occurrence, no abnormal instrumentation 3
?
upsets were observed. Pressure was maintained in the Reactor Coolant System. No ether abnormal incidents occurred.
I Corrective Action: As stated in the Description of Occurrence, the reactor was i==adiately shutdown to remove the station from the Action Statement.
x To prevent further recurrences, the Plant Shutdown and Cooldown Procedure, j
PP 1102.10.1, is being revised. Revision is being made to have the Auxiliary Boiler in service and the major steam loads transferred to the Auxiliary Boiler i
prior to decreasing reactor power to 10-8 amps.
4 i
Failure Data: No previous similar events have occurred.
i i
I 4
l i
i 6
a 5
\\v>
1 w-wa
+-t--
e<w-
'ww-ww w
w-
-,w-ry